There will be a lunar eclipse on December 20/21 (a rare one, occurring on the Winter Solstice to boot!). If you happen to be in the United States, this will be a very nice one to watch. It starts at 12:27 PM EST, finishing at 6:06 AM EST. The best viewing should be about 3:17 AM EST.
Tom’s Astronomy Blog has a very nice and concise description of the event. If you would like more information, there is another article over at Astonomy.com
Drag yourself and anyone else you can find out in the cold to enjoy one of natures finest events!